June 2015 Chemistry Regents #41-45
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Questions | Answer | Links | Explanations |
| 41 A mixture consists of sand and an aqueous salt solution. Which procedure can be used to separate the sand, salt, and water from each other? (1) Evaporate the water, then filter out the salt. (2) Evaporate the water, then filter out the sand. (3) Filter out the salt, then evaporate the water. (4) Filter out the sand, then evaporate the water. | 4 | link | salt dissolves in water and sand does not |
| 42 An aqueous solution has a mass of 490 grams containing 8.5x103 gram of calcium ions. The concentration of calcium ions in this solution is (1) 4.3 ppm (3) 17 ppm (2) 8.5 ppm (4) 34 ppm | 3 | link | (8.5x103 gram/490 grams) *1,000,000 |
| 43 A sample of hydrogen gas at 2.0 atmospheres and 273 K occupies a volume of 5.0 liters. The gas sample is completely transferred to a 10.0-liter sealed, rigid container. What is the new pressure of the gas sample when the temperature returns to 273 K? (1) 1.0 atm (3) 3.0 atm (2) 2.0 atm (4) 4.0 atm | 1 | link | PV=PV (temp stays the same) 2.0atm*5.0L= P*10.0L |
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| 44 Given the equation for a system at equilibrium: N2(g) + 3H2(g) ==>2NH3(g) + energy If only the concentration of N2(g) is increased, the concentration of (1) NH3(g) increases (2) NH3(g) remains the same (3) H2(g) increases (4) H2(g) remains the same | 1 | link | shifts right, products increase, reactants decrease |
| 45 A hydrocarbon molecule has seven carbon atoms in a straight chain. There is a double bond between the third carbon atom and the fourth carbon atom in the chain. The IUPAC name for this hydrocarbon is (1) 3-heptyne (3) 3-heptene (2) 4-heptyne (4) 4-heptene | 3 | link | lowest carbon with Double Bond is 3- 7 carbons...hept double bond...ENE
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